1. S. J. Radcliffe, Institution of Mechanical Engineers, Tribology Convention, Durham, March 1976 (The Institution of Mechanical Engineers, 1978).
2. E. J. Gumbel, ?Statistics of Extremes? (Columbia University Press, New York, London, 1958).
3. R. Irving and N. A. Scarlett, Institution of Mechanical Engineers, Lubrication and Wear Conference, Bournemouth, 1963.
4. N. P. Suh, Wear 25 (1973) 111.